Factors associated with survival in older patients affected by COVID-19: A retrospective cohort study.

Aim: Mortality is high in Coronavirus disease 2019 patients with pre-existing comorbidities and advanced age. Associated complications have added to the negative prognosis. Nevertheless, many have fully recovered, even among the most fragile. Factors associated with their survival was investigated.

Methods: Retrospective study of patients aged ≥90 years admitted for COVID-19 to the Internal Medicine wards of two hospitals in Lombardy, Italy.

Results: Among 34 patients with SARS-CoV-2 pneumonia, 33 (97.1%) had respiratory failure. Eighteen patients (52.9%) survived and 16 (47.1%) died during hospital stay. Survivors compared to deceased had a significantly longer hospitalization (19 vs. 10 days respectively; p = 0.02), a better PaO2:FiO2 ratio (241 vs. 171 respectively; p = 0.003), higher lymphocyte counts (p = 0.01) and lower serum LDH levels (p < 0.001) at admission. At multivariate analysis only higher PaO2:FiO2 was associated with survival (OR 1.06 [95%CI 1.0-1.03]; p = 0.02). Kaplan-Meier analysis showed a significant difference in event-free survival between patients treated or not with LMWH (p < 0.0001) and between those treated or not with beta-blockers (p = 0.008). Cox regression, performed in the subgroup of patients who received LMWH, did not show significant difference for sex (HR 2.7 [95% CI 0.53-14.3], p = 0.23), CCI (HR 0.7 [95% CI 0.37-1.45], p = 0.38), PaO2:FiO2 ratio (HR 0.98 [95% CI 0.97-1.0], p = 0.07), corticosteroid therapy (HR 0.99 [95% CI 0.22-4.5], p = 0.99) and beta-blocker therapy (HR 2.8 [95% CI 0.56-14,7], p = 0.21).

Conclusions: Despite higher mortality in elderly, treatment with LMWH and betablockers might be associated with better survival. Dedicated studies are required to confirm our result.